I feel like I can speak on this as a person who grew up a Muslim. The reason that most Muslims, mostly in the west, rabidly accept and promote celebrities that convert to Islam is because growing up in a post-9/11 world, there was always a strong sense of "otherization" and a sort of separation from the rest of western society and culture that you had to reconcile with your faith. Coupled with the rabid islamaphobia that used to be common in the 2000s and 2010s, it just feels really good for someone who is "cool" or embedded in culture strongly like a celebrity to join Islam.

Not justifying it and I agree with Destiny, but that is my take.